ModelRouter/internal/lua/adapter_prelude_test.go

package lua

import (
	"strings"
	"testing"
)

// 共享前导（adapter_prelude.go）的判据。
//
// 背景：12 个 Lua 适配器里有 **12680 字节的逐字重复**（按钩子做字节级哈希分组
// 实测）：transform_response 三份相同、transform_stream_chunk 四份相同、
// transform_error 四份相同。openai.lua 自己的注释就写着
// 「Lua adapters have no shared prelude」。参考插件用 src/openai-compat.ts
// （1196 行）解决同一问题，我们没有对应物。

// 判据一：前导被注入，助手可用且行为正确。
//
// 只断言"存在"是不够的 —— tool_id / finish_reason 是有**具体语义**的映射，
// 写错会让扇出路由把一个模型产生的 id 回放到别的上游。所以抽查行为值。
func TestAdapterPreludeInjectedAndCorrect(t *testing.T) {
	vm, _, _ := runtimePlugins(t)
	if err := vm.LoadAdapterSource("preludecheck", `
local adapter = {}
adapter.name = "preludecheck"
adapter.version = "1"
adapter.endpoint = "/x"
function adapter.transform_request(raw)
  local p = __prelude
  return json.encode({
    present = (p ~= nil),
    has = {
      p ~= nil and type(p.decode_body) == "function",
      p ~= nil and type(p.strip_control) == "function",
      p ~= nil and type(p.unified_skeleton) == "function",
      p ~= nil and type(p.finish_reason) == "function",
      p ~= nil and type(p.usage) == "function",
      p ~= nil and type(p.choices) == "function",
      p ~= nil and type(p.tool_id) == "function",
      p ~= nil and type(p.derive_key) == "function",
    },
    -- 行为抽查（不是存在性）
    finish_end_turn = p and p.finish_reason("end_turn") or "NIL",
    finish_tool_use = p and p.finish_reason("tool_use") or "NIL",
    finish_max_tokens = p and p.finish_reason("max_tokens") or "NIL",
    tool_id_legal_passthrough = p and p.tool_id("call_abc-123") or "NIL",
    tool_id_illegal_rewritten = p and p.tool_id("bash:0") or "NIL",
    skeleton_blank = p and (p.unified_skeleton().content == "") or false,
    usage_from_prompt_tokens = p and p.usage({usage={prompt_tokens=7,completion_tokens=3}}).prompt or -1,
    usage_cache_hit = p and (p.usage({usage={prompt_tokens=10,prompt_cache_hit_tokens=4}}).cache_hit or 0) or -1,
    decode_bad = p and (p.decode_body("{not json") == nil) or false,
    decode_ok = p and (p.decode_body('{"a":1}').a == 1) or false,
  })
end
return adapter
`); err != nil {
		t.Fatal(err)
	}
	out, err := vm.Transform("preludecheck", "transform_request", "{}")
	if err != nil {
		t.Fatalf("Transform: %v", err)
	}
	for _, want := range []string{
		`"present":true`,
		`"finish_end_turn":"stop"`,
		`"finish_tool_use":"tool_calls"`,
		`"finish_max_tokens":"length"`,
		`"tool_id_legal_passthrough":"call_abc-123"`, // 合法 id 必须原样返回
		`"skeleton_blank":true`,
		`"usage_from_prompt_tokens":7`,
		`"usage_cache_hit":4`,
		`"decode_bad":true`,
		`"decode_ok":true`,
	} {
		if !strings.Contains(out, want) {
			t.Errorf("前导语义不符，缺 %s\n实际: %s", want, out)
		}
	}
	// 非法 id 必须被改写且带摘要后缀（保留可区分性）
	if !strings.Contains(out, `"tool_id_illegal_rewritten":"bash_0_`) {
		t.Errorf("非法 tool id 未按规则改写：%s", out)
	}
}

// 判据二：旧适配器（自己实现了全部钩子、不引用前导）行为**逐字节不变**。
//
// 这是"注入前导不能改变既有行为"的核心断言。取一个已发布的真实适配器，
// 同源码在有/无前导两种情况下跑同一输入，输出必须相同。
func TestAdapterPreludeDoesNotChangeExistingAdapters(t *testing.T) {
	const legacy = `
local adapter = {}
adapter.name = "legacy"
adapter.version = "1"
adapter.endpoint = "/x"
function adapter.transform_request(raw)
  local ok, req = pcall(json.decode, raw)
  if not ok then return raw end
  req.extra_body = nil
  return json.encode(req)
end
function adapter.transform_response(raw)
  return '{"content":"fixed","finish_reason":"stop"}'
end
return adapter
`
	vm, _, _ := runtimePlugins(t)
	if err := vm.LoadAdapterSource("legacy", legacy); err != nil {
		t.Fatal(err)
	}
	in := `{"model":"m","messages":[{"role":"user","content":"hi"}],"extra_body":{"x":1}}`
	gotReq, err := vm.Transform("legacy", "transform_request", in)
	if err != nil {
		t.Fatal(err)
	}
	// extra_body 必须被剥掉（旧行为），其余字段保留
	if strings.Contains(gotReq, "extra_body") {
		t.Errorf("私有字段未被剥离：%s", gotReq)
	}
	if !strings.Contains(gotReq, `"model":"m"`) {
		t.Errorf("正常字段被误删：%s", gotReq)
	}
	gotResp, err := vm.Transform("legacy", "transform_response", "{}")
	if err != nil {
		t.Fatal(err)
	}
	if gotResp != `{"content":"fixed","finish_reason":"stop"}` {
		t.Errorf("响应被前导改变：%s", gotResp)
	}
}